Unrest at Redoubt Volcano continues. Seismicity at stations closest to the volcano's summit has declined somewhat starting at about 4:00 AKT this morning, but remains well above background levels.

Nothing unusual has been seen over the past 24 hours in clear to partly cloudy satellite views. AVO conducted an overflight of the volcano yesterday afternoon, and observations confirm that an eruption has not occurred. Increased steaming through previously observed sources in the snow and ice cover were seen and sulfur gas emissions were noted. There was no significant disruption of the glacial ice, nor any apparent increased water discharge down the Drift River. A gas-measurement flight to the volcano is underway today.

The current activity at Redoubt could be precursory to an eruption, perhaps within days. A further increase in seismicity is expected to accompany an eruption. Staff are currently monitoring the volcano 24 hours a day.

Beginning at 00:58 AST (9:58 UTC) yesterday morning, nearly continuous volcanic tremor was recorded at stations near Redoubt's summit, prompting AVO to raise the Aviation Color Code to ORANGE and the Alert Level to WATCH at 02:09 AST (11:09 UTC). AVO had raised the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY on November 5, 2008, in response to increased emissions of volcanic gases; melting of snow and ice near the volcano’s summit; and a subtle increase in seismicity.

A slight thermal anomaly was observed this morning at Shishaldin in satellite images. Snow and ice still obscure the volcano in the web camera images. Seismicity at Shishaldin remains unchanged over the last 24 hours.

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

VOLCANO ALERT LEVELS

NORMALVolcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.

ADVISORYVolcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

WATCHVolcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway but poses limited hazards.

WARNINGHazardous eruption is imminent, underway, or suspected.

AVIATION COLOR CODES

GREENVolcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.

YELLOWVolcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

ORANGEVolcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway with no or minor volcanic-ash emissions [ash-plume height specified, if possible].

REDEruption is imminent with significant emission of volcanic ash into the atmosphere likely OR eruption is underway or suspected with significant emission of volcanic ash into the atmosphere [ash-plume height specified, if possible].